Mine has the 26" barrel and patterns exceptionally well. Based upon what I've seen over the years, a 26" barrel, especially in those over bored guns is just about perfect. That's not to say that you can't get turkey killing patterns with shorter barrels, my SSi-ONE (same bore) has a 24" ported barrel and it does quite well.
Most of the folks who contact me with patterning "challenges" are shooting the shorter barrels however.
I'd recommend that you handle a 935 with a shorter barrel to see if you can feel the benefit of it before you go to the expense of purchasing one.
It may feel much better to you than the one you have or it may make very little difference.
Thanks,
Clark